In May of this year, my brief essays (literally, “attempts”) on synthetic human entities with embryo-like features, or SHEEFs for short, sought to ask what sort of human cellular constructs might or might not enjoy full human moral status; to wit, the right to life. Some experimenters with SHEEFs have suggested that, since they may bypass the early (14 days of life) markers that normal, or (if you will) canonical, human embryos demonstrate, a different moral approach is needed to determine ethical boundaries for these experiments, and the suggestion was that the capacity to feel pain would be a good substitute.
In my May 11 post, I suggested that a SHEEF with even part of a human nervous system must be accorded the right to life. I made what is, I confess, a breezy connection between said nervous system, however rudimentary, and the identification of a human soul, on the grounds that bodily expression of human capacities commonly is through the effects of the nervous system. The capability of any such capacities, I wanted to hold, would mark a SHEEF as a “human being” deserving of moral status. This would distinguish it from, for example, a tissue-engineered trachea, or a kidney, or maybe even a heart, although human heart have, in their automatic conduction systems, a sort of “nervous system” capacity, I suppose. Still, it didn’t seem to me (Edgar Allan Poe notwithstanding?) that a tissue-engineered heart would be considered a “human being,” the sort of being with “the intrinsic capacity to develop sentience, to ponder the universe, to comprehend the inevitability of mortality, to seek purpose, to yearn for love, and to suffer?”
That last quoted phrase is from a welcome essay by Dr. William Cheshire in the Fall 2017 edition of the journal Ethics & Medicine. In his essay, “The moral significance of pain for synthetic human entities derived from embryo-like cells,” he argues, to put it all too briefly, that the ability, the realized capacity, to feel pain is an inadequate marker of human moral status. Why? Because some humans are incapable of nociception—physical responses to noxious stimuli. Indeed, local anesthetic makes an otherwise fully-thriving human numb, for a while. To say that all SHEEF experiments are OK as long as the entity doesn’t feel pain is to reduce meaning to pain, pleasure, and happiness. Dr. Cheshire muses about a hypothetical creature, designed and bred in the laboratory, that is “sentient…possessing a complete brain composed of human neurons, yet lacking critical genes necessary for the capacity to experience pain…Rather than ask, what does it mean for a human organism to experience pain, a better question is, what does it mean to be the kind of being that experiences pain? What does it mean to be the kind of being who has “the intrinsic capacity to develop sentience,” etc?
I was surprised when I saw that Dr. Cheshire chose for an epigram to his essay this sentence from my May 11 post: “A moral boundary is approached when a human nervous system is brought into the plan.” I read his essay as a criticism of my approach, but I still think the latter has merit. I still think that some human tissue engineering with some SHEEFs might be ethical. At the same time, I think that attempts to make too complete, too complex a SHEEF—for example, one with a whole human body except the head—would be monstrous. I suppose that such a being would have to have a fair amount of human autonomic nervous system to function at all, and so would fall under my criterion. And I also think that a quest for a “minimal human genome” or a “minimal human” would be frankly unethical. (I understand synthetic biologists to be interested in the former but nobody to be suggesting the latter.) To be ethical, experiments would have to observe serious limits from the concept stage. And a concept of “how far can we go before we truly have the kind of being with the intrinsic capacity…?” would be out of bounds.
Check out this June 15, 2017 cartoon from the New Yorker